The focus of the current research is twofold: 1) to develop statistical methods for modeling the complexities of familial social relationships when only partial information is provided; and 2) to utilize social network methodologies to understand the how the family cultural and social context impacts the diffusion of hereditary risk information, as well as coping with risk status. This research considers the social context in which at-risk individuals live, allowing us to better understand the impact of families? interpersonal environment on behavior. [unreadable] [unreadable] Currently, we have developed exponential random graph models (ERGMs) for partial networks. These models accommodate network data that have been obtained using cascade sampling or snowball sampling designs or where eligible respondents have declined participation in the study (NHGRI Protocol # 05-HG-N249; PI: Laura Koehly). The 80 interview transcripts from members of 13 families with known mutations for hereditary nonpolyposis colo-rectal cancer (HNPCC) have been coded and will be used to illustrate the statistical models that have been developed for partial network data. We will be using these models to investigate the role of the familial social structure in communications about genetic testing and counseling and disclosure of mutation status. Preliminary analyses indicate that dissemination patterns of hereditary risk information are not only related to biological relationships. Although family members tend to discuss family risk with their first degree relatives, they reach other family members through their social relationships as defined by cohesiveness, advice-seeking, and lack of conflict. The accuracy and robustness of the ERGMs for partial networks will be evaluated using complete network data that will be obtained from an ongoing study examining the role of the familial social context in disclosure of family risk information, screening behaviors, and adjustment to risk status (NHGRI Protocol # 95-HG-0165; PI: Don Hadley). We anticipate that we will begin recruitment of both at-risk and not at-risk family members from 44 families with identified HNPCC germline mutations within the next two months. These individuals will be asked to provide information regarding their family relationships (e.g. cohesiveness, support, and conflict) as well as the communication of family risk information. Additionally, we are investigating the role of social support processes in women coping with their hereditary risk for breast-ovarian cancer (NCI Protocol # 01-C-0009; PI: Jennifer Loud). This research uses the Colored Eco-genetic Relationship Map (CEGRM) to assess the social support networks of study participants. Currently, 190 participants have been recruited into the study. CEGRM assessments and psychosocial measurements are obtained at baseline and at three annual follow-ups.